I have the evga 650 ti boost 2gb (no sc) this card have a nice FAN, but here is too hot (like 25-30°C) so I always play with the max fan spd. 3350rpm (74%) and the temp. is 67°C playing Crysis 3 overclocked to 1201mhz core and 3348 (+345) memory. But I'm worried about the Memory temp, I don't know it is safe to play all my games with that vRAM OC. I don't want to damage the memory by heat. I overclocked the vram to +500 and never show any artifacts, just a TDR.

Memory chips can handle about 90c so u should be fine. Heat will affect your vram overclocking headroom well before then though. If you got BSOD and no artifacts the voltage was prob too low, however I don't recommend raising it. You had a pretty good OC on stock before it TDR so maybe just drop the clocks a little..

I touched the vram and they're really really hot, but its normal I guess. I'll use +345 keeping on eye. Thanks for the reply.

I am at 7200 +600 but I have a backplate on the back of the cards that cool the vram somewhat. I would go for a 10% oc around 600mhz